1. Technical Field
The present invention relates to a method of generating frame control signals for reducing reaction time and, more particularly, to a method of generating frame control signals while reducing reaction time of liquid crystals.
2. Description of Related Art
Recently, with the progress of display industry, in addition to the gradual advancement and maturity of hardware processes for display devices, the display technologies applied to display devices have also developed continuously. For example, the technologies of field sequential color (FSC) and high dynamic range (HDR) have been introduced in the attempt to improve the displayed frame quality of display devices.
The FSC technology works by separately displaying a red sub-frame, a green sub-frame and a blue sub-frame, which are later integrated in a viewer's visual system. The FSC technology achieves chromatic display without a need of color filters so as to enhance light efficiency and save the costs for color filters, resulting in reduced manufacturing costs for an overall LCD device.
However, a display frequency of such chromatic frame is 60 Hz, meaning that only if 60 chromatic frames are displayed in each second, the chromatic frame is successfully displayed. Also, each of the chromatic frames is formed by sequentially displaying a red sub-frame, a green sub-frame and a blue sub-frame. This is to say, each said chromatic frame has to be displayed in 16.7 milliseconds and there is only a period of 5.6 milliseconds for displaying each said sub-frame. Yet, the work of controlling the liquid crystal rotation and changing the liquid crystal transmission can consume 2 to 3 milliseconds or more therein. Hence, a need exits for improving LCD display technologies by reducing the reaction time of liquid crystals.
Besides, according to the principle of the FSC technology, in order to reproduce the color information of all the pixels in a chromatic frame through the human visual system, the color fields of the three primary colors contained in the color information must be projected to a very point in the viewer's retina. If the color fields are otherwise projected to different points in the retina, the viewer's visual system can detect such deviation and makes the viewer catch an image with separated and deviated color fields, namely a CBU (color break-up) image. As color break-up can significantly debase display quality, it is a serious problem to be solved in the FSC technology.
On the other hand, the HDR technology is based on adjusting the backlight brightness of each display region in the frame according to the distribution of brightness over the displayed image. For example, in a display region where a dark portion in the image is to be displayed, the backlight is lowered or even turned off so as to prevent light leakage caused by imperfect liquid crystal alignment or failure of two polarizers in fully blocking downward backlight at a large view-angle. Thereupon, the contrast of LCD devices can be enhanced and the power consumption of LCD devices can be reduced.
The control signals are typically loaded from the upper left corner toward the lower right corner of the LCD device and properly rotate liquid crystals to change the liquid crystal transmission. However, since the reaction time of the liquid crystals is quite long, it tends to happen that the upper left liquid crystals have been already rotated to proper positions while the lower right ones have not yet, resulting in blurred images and incorrect color display. Therefore, if the reaction time of liquid crystals can be reduced, the refresh frequency of liquid crystals can be increased and the effect of mitigating image blur can be in turn achieved.